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Diffstat (limited to 'doc/development/database_review.md')
| -rw-r--r-- | doc/development/database_review.md | 2 |
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diff --git a/doc/development/database_review.md b/doc/development/database_review.md index a624abc2929..0cd7e083e2a 100644 --- a/doc/development/database_review.md +++ b/doc/development/database_review.md @@ -124,6 +124,8 @@ the following preparations into account. - Follow the [guidelines on dropping columns](what_requires_downtime.md#dropping-columns). - Generally it's best practice (but not a hard rule) to remove indexes and foreign keys in a post-deployment migration. - Exceptions include removing indexes and foreign keys for small tables. +- If you're adding a composite index, another index might become redundant, so remove that in the same migration. + For example adding `index(column_A, column_B, column_C)` makes the indexes `index(column_A, column_B)` and `index(column_A)` redundant. ### How to review for database |